2 papers
math.CO2016
Topologically -chromatic graphs and signatures of odd cycles
Gord Simons, Claude Tardif, David Wehlau
We investigate group-theoretic "signatures" of odd cycles of a graph, and their connections to topological obstructions to 3-colourability. In the case of signatures derived from f…
math.CO2016
Generalised Mycielski graphs and bounds on chromatic numbers
Gord Simons, Claude Tardif, David Wehlau
We prove that the coindex of the box complex of a graph can be measured by the generalised Mycielski graphs which admit a homomorphism to it. As a consequence,…